To make my argument clearer: this 'POINT( ? ? )' might look like an SQL function but it's a string which is parsed by ST_GeomFromText() !

Please note the missing commas, too. Function arguments in SQL are comma separated.

The MariaDB documentation calls the argument a WKT with T for Text! °

WKT is not SQL, pretty much like SQL is not Perl

Your string passed here to ST_GeomFromText() will always include literal question marks in your example.

There is nothing like ? placeholder handling inside strings in SQL!

The error you get will be along the line "too many arguments for placeholders" because the two ? inside a string are just ignored.

°) The Well-Known Text (WKT) representation of Geometry is designed to exchange geometry data in ASCII form

• https://mariadb.com/kb/en/st_geomfromtext/
• https://mariadb.com/kb/en/wkt/

update

• WP: Well-known text representation of geometry